The process of this invention permits the efficient peeling of citrus fruits so that individual segments of the fruit can be readily prepared. As is well known, citrus fruit has an outer peel and inner fruit segments separated from one another by membranes that also surround each individual segment. Between the outer peel and the membranes surrounding the individual segments is a white, pithy material known as the albedo.
In the past, citrus peeling has been accomplished by hand peeling the skin and removing the albedo to expose the fruit segments. Typically, the skin peeling and albedo removal has been done with a knife, which leads to removal and loss of some of the fruit. Complete removal of the albedo, and its white color, from the fruit segments requires additional processing time and care.
Peeling methods using mechanical equipment of various types is also known to those in the business. Generally, however, such mechanical peeling processes leave the peeled fruit in a condition that still requires hand removal of some portion of the albedo.
Processes have also been proposed to use an enzyme, such as pectinase, to dissolve and/or weaken the albedo so that the skin can be removed from the segments of meat inside the citrus fruit. For example, U.S. Pat. Nos. 5,170,698 and 5,196,222 to Kirk concern a process and related apparatus to peel citrus fruit where the fruit is perforated, given an equatorial cut, and deposited in a canister. The canister is filled with an albedo degrading solution, such as an aqueous solution of commercial pectinase, or a mixture of enzyme solutions. The albedo degrading solution is vacuum infused into the fruit to substantially disintegrate the albedo of the fruit.
Another peeling process simply removes a strip of citrus outer peel substantially at the equator of the fruit. The fruit is immersed in an enzyme solution. Then, a vacuum is applied to remove air from the citrus fruit and released. See, for example, U.S. Pat. No. 5,989,615.
Another possible peeling process involves submerging fruit in a fluid followed by the application of a vacuum. The vacuum may be applied in one or two steps. Thereafter, the vacuum is released and pressure is applied to the fluid. The fluid may contain pectinase. See, U.S. Patent Publication US 2004/0043126.
It has been found, however, that those prior art methods do not function well when scaled to commercial operations.